Neurosurgery, particularly neurosurgery on the brain, typically requires the precise positioning of a surgical tool within a body organ of extreme sensitivity. For example, when performing neurosurgery on the brain to excise a tumor, a surgical probe must be advanced into the brain along a precise route and precisely positioned adjacent the tumor to be excised. In brain surgery, a mispositioned or misrouted surgical probe, even if only slightly mispositioned or misrouted, can have disastrous consequences.
Not surprisingly, devices have been introduced which provide for the precise orientation and positioning of surgical tools within the brain, and which also support the surgical tools to prevent unintentional movement of the tools, once properly positioned. Several examples of such devices are set forth in Tumor Stereotaxis. More specifically, Tumor Stereotaxis discloses many types of stereotactic frames that can be fixedly attached to the skull of a patient to establish an external reference frame for the patient's brain. Additionally, the stereotactic frames disclosed in Tumor Stereotaxis can be used to precisely position and orient a surgical tool in the brain. More particularly, stereotactic frames typically have one or more movable arms, and at least one of the arms has a support bushing through which a surgical tool can be positioned. By positioning the surgical tool through the support bushing and then orienting the arms as desired, the surgical tool can be placed in a predetermined orientation relative to the brain.
Unfortunately, stereotactic frames have several drawbacks. For example, stereotactic frames are relatively complicated, bulky instruments. Consequently, they can interfere with the surgical procedure. Also, stereotactic frames ordinarily support the neurosurgery probe at a point that is relatively distanced from the skull of the patient. This limits the range of motion through which the probe can be pivoted, thus limiting the range of orientation of the probe vis-a-vis the skull of the patient.
Manually supporting a surgical probe in a precise orientation relative to the brain is ordinarily unacceptably cumbersome, and can result in inexact positioning of the probe. Further, existing stereotactic frames, even when used only for supporting surgical tools, interfere with the surgeon's range of motion. There is therefore the need to provide an apparatus which can hold a surgical tool in a precise predetermined orientation relative to the brain, and result in minimal interference with the surgeon's range of motion.
Thus, it is an object of the present invention to provide a relatively small, simple device for precisely orienting a surgical tool relative to a patient's brain. It is another object of the present invention to provide a device which can support a neurosurgery tool, without need of a stereotactic frame. Yet another object of the present invention is to provide a device that is easy to use and cost effective to manufacture.